The attachment governor.The attachment governor is a piece of code inside IB, created to enforce the number of attachment allowed in the server simultaneously. When an IB license is purchased for IB5.X, a number of maximum simultaneous users is allowed. Since each user can have more than one attachment, what the governor does really is to ensure that the maximum number of concurrent attachments is not more than 4 times the number of users allowed in the license file.The number of attachments changes as new users log on and log off from the server. The maximum is for the server, not per each database. This means a license for 10 users allows up to 40 attachments, either 40 attachments by one user or one attachment done by each one of 40 users or whatever combination produces a number of attachments that don't exceed 40. The attachments can be done to only one database or scattered through several databases available to the IB server that holds the licenses. Once the maximum number of attachments is reached, the server returns the error constant isc_max_att_exceeded (defined in ibase.h), which corresponds to the message: They key point to remember is that the limit is for concurrent attachments, namely, for attachments that happen at the same time. So, if an organization has 100 users but only 30% of them connect at the same time to the server with one attachment per user, such organization in practice could acquire a license for only 10 users, hence 40 simultaneous attachments are possible, but this is left to the legal experts. Take into account that IB6, since it's a free and open source product, it no longer uses the attachment governor, since no fees are charged for using it even in commercial organizations. |
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This page was last updated on 2000-08-30 01:52:51 |